This invention relates to satellite antenna horns and particularly to a satellite antenna feed horn arrangement for receiving both C-band and Ku-band signals.
The use of satellite receiving dishes has now become commonplace for consumers as well as commercial customers. The vast majority of these dishes include a feed horn and a low noise amplifier (LNA) for receiving broadcasts transmitted on the so-called "C-band" at frequencies of approximately 4 GHz. More recently however a second generation of geosynchronous satellites have begun transmitting on the "Ku-band" at 12 GHz. Reception of Ku-band signals by C-band antennas and amplifying systems is generally not practicable as low noise block converting amplifiers (LNB's) capable of amplifying both Ku- and C-band signals have generally been prohibitively expensive. Furthermore, a satellite dish owner is unlikely to want to discard a working C-band LNA in order to replace it with a dual band LNB. However, LNB's specifically designed for Ku-band operation are relatively inexpensive.
Since there is quite a large base of installed C-band antennae it is desirable to provide a means to permit relatively inexpensive reception of Ku-band signals with a preexisting C-band antenna. The present invention provides a feed horn arrangement to permit separate C-band and Ku-band LNB's to be mounted on a single dish without cross interference.
It has been found that a relatively narrow diameter dielectric rod will form a waveguide for Ku-band signals. Furthermore, such dielectric rods are substantially transparent to C-band signals. Accordingly, the feed horn arrangement of the present invention includes a dielectric rod mounted within the pre-existing C-band waveguide to direct Ku-band signals to a separate Ku-band feed horn and LNB. The Ku-band waveguide has no effect on the C-band signals which are amplified by the standard C-band LNA. The dielectric rod waveguide may be either straight or curved depending on the configuration of the C-band amplifiers and polarizers.
Accordingly, it is an object of this invention to provide a feed horn arrangement capable of permitting C-band and Ku-band reception with a single satellite antenna.
It is another object of this invention to provide retrofitting of Ku-band reception apparatus to C-band satellite antenna reception apparatus.
It is another object of this invention to provide both C-band and Ku-band reception capabilities to a satellite antenna without the need for a dual frequency LNB.
Still other objects of this invention will become apparent upon a reading of the detailed specification to follow.